1. Field of the Invention
The present invention relates to a projection-type display apparatus.
2. Description of the Related Art
Keystone correction is conventionally used to correct a distortion of a projection image of a projector through image processing (Japanese Patent Laid-Open Nos. (“JPs”) 2001-339671 and 2005-159829) and manual keystone correction is also available. In the manual keystone correction, a user inputs a vertical keystone value and a horizontal keystone value separately. Lens shift correction is also conventionally used to correct a distortion of a projection image of the projector through optical processing.
For both the keystone correction and the lens shift correction, vertical and horizontal correction parameters, such as a vertical keystone correction value and a horizontal keystone correction value, are correlated with each other, and thus as one of them is corrected a correctable range of the other varies. However, the conventional keystone correction or lens shift correction does not provide to a user the correctable range of the other of the correction parameters which varies as one of the correction parameters is corrected, and thus the operability is poor.